Hitachi ZAXIS 135US-5B Operator's Manual page 409

Problem
Only one actuator is inoperable
Only one cylinder is inoperable or has
no power
Hydraulic oil temperature increases
Oil leak from low pressure hose
TROUBLESHOOTING
Cause
Broken control valve spool
Embedded foreign matter in valve spool
Broken pipe and/or hose
Loose pipe line joint
Broken O-ring at pipe line joint
Broken actuator
Faulty pilot valve
Faulty pilot circuit line
Faulty pilot solenoid valve
Broken oil seal in cylinder
Oil leak due to damage to cylinder rod
Faulty pilot valve
Faulty pilot circuit line
Faulty pilot solenoid valve
Stained oil cooler
Insufficient engine fan belt tension
Loose clamps
Faulty suction manifold
11-5
* Replace
* Repair or replace
* Repair or replace
Retighten
* Replace
* Repair or replace
* Replace
* Repair or replace
* Repair or replace
* Repair or replace
* Repair or replace
* Replace
* Repair or replace
* Repair or replace
Clean
Adjust
Retighten
* Repair or replace
Items with * mark: Consult your nearest Hitachi dealer.
Solution